


Denial is not a river in Egypt

by yagisa



Series: O Master, My Master [1]
Category: Fate/Grand Order
Genre: Alpha/Beta/Omega Dynamics, F/M, Not Beta Read
Language: English
Status: Completed
Published: 2019-01-14
Updated: 2019-01-14
Packaged: 2019-10-09 23:28:31
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,833
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/17414594
Author URL: https://archiveofourown.org/users/yagisa/pseuds/yagisa
Summary: In which Robin Hood has the misfortune of finding out his Master's secret at the most inopportune moment.





	Denial is not a river in Egypt

**Author's Note:**

> Characters appearing in this oneshot are based on who I have in my Chaldea.  
> I'm ABO trash but I took a lot of liberties with this one. Please take it with a grain of salt as everything was written in pure fun and thirst over Robin Hood. Please give this beautiful forest hobo more love!
> 
> Also this is unbeta'd, so yeah. There may be mistakes that I missed.

It takes approximately three months and two weeks before Robin realizes that Ritsuka is in fact an _omega._

And to further his embarrassment, the means by which he comes upon the _highly relevant_ information is in no way due to his skills of stealth and observation— _he’s an archer, not an assassin, damn it_ —he simply happened to be at the wrong place at the wrong time.

( _Billy argues that he was at the **right place at the right time** , but Robin disagrees. Strongly. Billy liked to claim a lot of things that were untrue; like that one time he said that Ritsuka was mooning over him just because she gave him a valentine’s present._

_“Robin, she gave you a homemade chocolate shaped like your Yew Bow.”_

_“She gave everyone chocolates. Even that Red Archer had one.”_

_“There were hearts on the wrapping paper of your gift. Lotsa them.”_

_“She was just being nice.”_

_“Right. Whatever you say man, whatever you say.”_

_See? How utterly ridiculous._

_Point is, Billy can’t always be trusted._ )

* * *

The inciting incident _—_ Geronimo tells him that he’s being far too dramatic, but Robin feels justified in this case _—_ starts innocently enough. 

With a small team of four servants including himself, Ritsuka rayshifts into one of the many islands of Okeanos for an ember gathering quest.

The infuriating Red Archer is on the frontlines, clearing waves and waves of enemies all by his lonesome while the tiny little murder child _—_ _Jack,_ he mentally corrects _—_ is off to the sidelines wringing stars from wyverns with the same ease one had when squeezing juice out of an orange. From the rear end of the battlefield, Hans offers support, repeatedly casting buffs to ensure the duo’s success while mixing very loud grumbles of discontent in his incantations. 

Meanwhile, Robin hides behind a particularly dense thicket of trees, picking off the enemies from afar as he plays guard to Ritsuka. If he’s to be honest, he hardly thinks that he’s the best choice of bodyguard but Ritsuka _—_ _bless her stupidly sincere heart—_ has so much faith in him that he literally can’t find it in himself to say no when she looks at him with that pleading expression in her eyes.

...Besides, if he’s to be honest, it's kind of nice to have someone depend on him wholeheartedly like this. Perhaps if he had someone like her when he was still alive then—

 _Nope._ He’s not going there. That’s a can of worms he’s not about to open. There are far more worthy candidates of his Master’s affections than he.

Robin’s eyes flick to the back of the Red Archer’s head. His jaw tightens minutely.

Yeah. Definitely better options.

“Robin…” A soft hesitant voice tears him from his thoughts and he feels a soft tugging on his cape.

“Yes Master?” He replies after taking down his fourth pirate. He immediately turns his attention to Ritsuka, assessing her for injuries _—_ unreliable he may be, he’s not heartless enough to leave his curious Master injured _—_ but she looks fine aside from the sudden redness that dusts her cheeks. There’s a sheen of sweat covering her exposed skin and Robin can’t help but frown in concern. “Master, you don’t look so good, are you alright?”

“Mmhmm,” Ritsuka hums, languidly playing with the fabric of his cape. “M’fine now.” She looks up at him with glazed eyes before giving him a lazy smile that brightens her face.

Robin briefly wonders if she had somehow gotten herself drunk. It wouldn’t be the first time she’d rayshift while hungover.

He cocks his head to the side. “Have you been drinking with Jing Ke again?” Without waiting for a response, he leans over Ritsuka’s shoulders to scent out the smell of alcohol. His nose hovers a few inches away from her neck and he half-heartedly expects to find the dizzying scent of hard liquor. Instead, he finds himself with a sudden lungful of Ritsuka’s scent; bland Chaldea-issued soap coupled with the acidic scent of magecraft. This time however, there’s a vague undertone of something _sweet_ just beneath the stale scent of mana.

Robin’s face pinches in confusion.

_Is it a new perfume fragrance?_

To his knowledge, Ritsuka frequently hung out with Mata Hari. They had bonded over their shared interests and would regularly _“shop”_ at different eras just to find the prettiest trinket and shiniest bauble they could find.

Maybe the sweet scent was from one of the new perfumes they’d bought?

Yeah. That’s probably it.

But before Robin can inquire any further about it, Ritsuka flings her entire body at him, burrowing her head underneath the crook of his chin. Then to make it even worse, she presses her hips against his and lets out a moan that Robin will forever deny having ever fantasized about.

Robin’s brain shuts down for a total of five seconds, drowning itself in the bliss that was Ritsuka’s warmth. But at another brush of Ritsuka’s hips against his di— _his pants_ —his brain finally decides to cooperate with him.

“ _Master!_ ” His first instinct, of course, is to push her away and set an appropriate distance between the two of them. But as soon as his hands land on her shoulders, he finally notices the heat radiating from her body. Dutifully ignoring the next moan that tears from her parted lips, he gingerly places the back of his hand against her forehead. “Master, you’re running a fever, we need to get you back to Chaldea!”

The gravity of the situation seems to be lost on Ritsuka and she simply gives him another slow smile. “Mmhmm,” She sighs, pulling his hand to rest against her cheek before rubbing against it, making little noises of contentment. 

This time it’s Robin’s turn to flush and he quickly withdraws his hand from her grasp as if he’d been scalded. Ritsuka makes this disappointed noise from the back of her throat _—_ almost a whine _—_ but Robin does his best to ignore it like he ignores the many admittedly appealing parts of Ritsuka’s personality. 

Geronimo says that he’s being willfully oblivious but that is neither here nor there.

Robin takes a few steps away from her, composes himself, and then says.

“Master, let’s rayshift back to Chaldea. I’m sure the others will manage just fine without us.”

Ritsuka makes this ~~cute~~ grabby motion with her arms but Robin promptly sidesteps her.

“You should take a few days off, I’m sure no one will mind. After all, the health of our Master is more important than anything.”

Ritsuka whines, making another attempt for his cloak but Robin makes a break for the other end of the forest’s clearing. _Bless the Holy Grail for his B-rank agility._

“Now, I know you’re very eager to summon new servants but that’s no excuse for being neglectful of your health.”

In the distance, he hears the sound of Emiya’s and Hans’ incantation dying down. _Finally._ All he has to do is stall her for a few more minutes and then the Red Archer can finally whisk her away to the safety of Chaldea’s halls.

“And hey, maybe this time you’ll get lucky and get a much more reliable archer like the King of Heroes— _Master, what are you doing?!”_ With an agility that almost parallels the Assassin class, he darts over to Ritsuka's side, wrapping his cloak around her unexpected and very naked form. But even with the roughhewn cloth around her ( _Goddamnit, this is not the proper use of his Noble Phantasm!)_ , he can still feel the heat emitting from her body.

On the ground is her discarded mystic code. A hint of something pink and lacey peeks out from between the dark pair of stockings.

 _Oh,_ Robin’s mind supplies, _is that her underwear?_

He squints at it. 

His mouth goes dry. 

_Yeap. It is indeed Master’s underwear._

He pointedly looks away from the distracting pile and tightens his grip around Ritsuka if only to ensure that she doesn’t run butt-naked into the battlefield. “Master,” He says slowly. “Why are you naked?”

From between his arms, Ritsuka squirms in his coat, looking entirely too pleased at their proximity, like a fat lazy— _albeit very endearing_ —cat that had finally found a good spot to sun itself at. “Because I wanted to be close to you,” She sighs happily into his chest and Robin feels his heart nearly stutter to a stop. “'like your scent. 'feel safe with you.”

He swallows thickly. “I— _thank you?_ ” The sudden admission makes Robin’s nonexistent heart clench painfully and he feels the tips of his ears go hot.

Frankly speaking, having a Master like Ritsuka could get a little more than overwhelming at times. He was unaccustomed to the wholehearted trust and adoration she’d deigned to bestow upon him—the four grails in him were a testament to that—despite his admittedly cowardly and underhanded battle tactics.

And yet, Ritsuka hadn’t minded that one bit and even felt comfortable enough in her weakened state to trust him with her life. He wasn’t much of an alpha back when he was alive and even as a servant, his habits and actions weren't very representative of his dynamic. But nevertheless, a swell of protective instinct surges from within him and Robin snakes a shaky arm around Ritsuka's shoulder, tucking her against his chest. 

His Master makes this little happy noise, sounding inordinately pleased at their lack of distance.

Oh.

_Oh._

_This is nice,_ Robin thinks to himself as he rests his chin atop her orange head, his other hand lazily petting the small of her back. _And comfortable,_ a traitorous part of his mind adds. _Perhaps if he just spirited Ritsuka away for a bit, no one would notice?_

He looks down at Ritsuka who had taken to rubbing her cheeks against his shirt. A small smile forms on his lips. 

_Yeah. Looks like Master isn't entirely opposed to it_

Robin has the half coherent idea formed at the tip of his tongue when Emiya storms into the clearing, looking highly scandalized.

“What the hell is going on here?” Hans and Jack pop out from behind him, surveying the scene with mild interest.

And as if a spell had been broken, Robin’s thoughts instantly snap into clarity and a look of mortification crosses his features.

“Wait. _Wait. Wait!_ I can explain! It’s not what it looks like!”

Hans raises a skeptical brow.

“I have a perfectly valid explanation for this!”

Emiya eyes the discarded pile of clothes in barely concealed doubt.  

“She undressed herself!”

Jack raises her daggers menacingly.

“What kind of person do you guys take me for?! _Geez._ Please cut me some slack, I’m nothing like that other green archer!”

“No. You’re far worse. At least David is honest about his tendencies.”

“ _Oi._ Take that back. I’m nothing like that womanizer!”

“Says the man who has a naked woman wrapped in his Noble Phantasm.”

“I was trying to stop her from running naked!”

“A flimsy excuse.”

“ _It’s the truth!_ ”

Emiya looks like he wants to argue some more but Ritsuka takes that exact opportunity to let out another loud and _highly_ lewd moan as she rubs herself _again_ against Robin’s di— _pants._

“Robiiiiiiin,” She whines.

Robin promptly snaps his mouth shut, unable to find the words to defend himself.

Luckily for the Green Archer, its at that moment that Hans takes pity on him, tiring of their little comedy skit.“Oh for the love of— _Archer,_ stop baiting him. We’re all wildly aware of your predilection for caustic bantering, but now is not the time for such nonsense. Master clearly needs your help.”

Emiya mumbles something under his breath but a withering look from Hans quickly shuts him up. 

“Little murderous child! I can see you, you know. Stop trying to dismember the poor man. Master won’t appreciate it if you go off murdering all of her potential paramours.”

Jack withdraws her daggers, looking utterly unrepentant.

“And you! May King! I know your hormones are on the same level as a teenage boy who has just discovered illicit material for the first time—”

_“Excuse me?!”_

“—but reign it in! I doubt that the forest is an ideal place for ravishing Master during her heat.”

“Her heat?!” He chokes out.

“Yes. Her heat.”

“But— _but—_ ” Robin splutters. “Betas don't have heats!”

Hans looks at him incredulously. “Whatever gave you that idea? Master is clearly an omega.” His nose crinkles and he raises a sleeve to cover his mouth. “Can’t you smell it on her? Even as a beta, I can tell that the air is thick with her pheromones.” A considering look crosses over Hans' features, before he continues, "Though ever since you've swaddled her in that ratty cloak of yours, the scent of her pheromones seems to have abated. Hm. How interesting, it seems we have found yet another use for your worn cape. Rejoice, May King."

There are too many things Robin wants to retort in response— _like how an alcoholic old man who looked like a child had no right dissing his Noble Phantasm_ —but he settles for a strangled noise. “I— _what.”_

Emiya huffs, impatient. “Might I suggest you hand Master over to me, _now_? We need to get her back to Chaldea as soon as possible. Normally, I’d trust you with such a task but—” The Red Archer sweeps a look over Robin’s person and his gaze rests somewhere down below before an amused smirk slants on his mouth. “Yeah, you’re definitely not going anywhere with her like that.”

Robin looks down and hisses out a particularly uncouth curse. It seems that his little friend has decided to take that moment to _rise_ into the occasion. He growls in embarrassment, turning his body away from the would-be voyeurs but makes no attempt to address it. Ritsuka, for her part, appears to be happily glued to his side, purring and nuzzling against him as if her very life depended on it. 

(There are  _some_ whispers of adoration and promises of affection that slips from her lips as well, but everybody does their best to ignore it with a straight face. Especially Robin.  _Most especially Robin._ )

"As if she'd be any safer with _you_." He says instead. Robin may be willfully ignorant of a lot of things, but he's not blind to Ritsuka's fondness for the Red Archer. Billy says that it's just his self-flagellating nature talking, but he knows for a fact that there's  _something_ going on between the two if their not so secret late night rendezvous are anything to go by. 

Emiya gives him this strange look. "And why wouldn't she be any safer with me?"

 _Seriously?_ Was he going to feign ignorance at this point? "Because you're an alpha, and Master is an omega. _In heat._ " Robin still feels like he's in a surreal fever dream at the abrupt revelation, but he's nothing if not highly adaptable. So he narrows his eyes at the other Archer, his grip tightening on Ritsuka's shoulder. 

But instead of rising to the challenge or showing any sign of aggression, Emiya just looks like he's swallowed a very sour lemon. He groans, massaging his temples. 

"Yeah, I had a feeling it was something like this." Emiya exhales, suddenly looking very tired. From his side, Hans gives him a sympathetic pat on the arm. "Gods. I hate alpha posturing, I truly do. Why do you alphas always jump to the most inane of conclusions? Honestly. It's as if you always think with your dicks."

Wait.

_What._

Robin remains rooted on his spot, unblinking. But there must be something in his expression that betrays his inner turmoil because Emiya releases this long-suffering sigh and drops an even bigger bomb on him. "I'm an omega, you idiot. And before you go on some annoying tirade on dynamics, let me be the first to state that I have no intentions of bonding with Master." An expression that's _almost_  affectionate rests on Emiya's face as he looks at Ritsuka's form snuggled up next to him. "And it appears that neither does she."

* * *

 "Hey, hey, have you heard of the new rumor?"

"You'll have to be a little more specific than that, intruder boy. There are several rumors always afloat in Chaldea."

"Oh come on, Geronimo, you know the one."

"If you're referring to the sudden revelation that our dear companion is still reeling from, then yes, I have heard of it."

"Great. Now for my payment?"

"Ah, but that is where you are wrong my friend. Our wager was specifically for when Robin would realize his  _feelings_ for Master, not for when he realized her nature."

"But he pretty much admitted that he wanna bones her! Surely that counts for something!"

"Feelings, Billy. We agreed on feelings."

Frustrated, Billy turns on his heel with a groan, unaware of the secretive smile that plays on Geronimo's lips.

Now, if only he could convince Robin that Emiya's and Ritsuka's relationship was on a strictly parental level. 

**Author's Note:**

> Some notes, apparently Robin's other NP, specifically No Face May King (his green cloak) has the capability to hide things underneath it. It can suppress some traces of magecraft which, in this fic, translates as his cloak helping with masking Ritsuka's scent and magic, which is why he doesn't really notice it until Hans points it out. But of course, he's also willfully oblivious so there's that too.


End file.
